The investigational product is Kiovig a brand of immunoglobulin. Kiovig
will be compared to Gammagard (another brand of immunoglobulin).
The first phase is a randomised dubbel-blind phase, where patients
receive 1 infuse Gammagard, followed by 4 blind gifts (Gammagard or Kiovig) The second phase ia an open-label
phase where all patients recieve 5 gifts Kiovig.

- Primary outcome

1. The efficacy. The ODSS will be used as the primary outcome scale. A change of more than one point will be considered as improvement or worsening.
2. The vigorimeter and MRC sumscore will be used as secondary outcome scales.

- Secondary outcome

1. The secondary objective will be to record the occurence of side-effects;
2. The preferences of patients regarding the medication.

In practise CIDP patients are treated with different brands of immunoglobulins that are considered to hace comparable efficacy, although this has not been formally investigated. Kiovig is a registered immunoglobulin which is easy to administer and can be infused faster. the first fase is a randomised double blind where patients receive either Kiovig or Gammagard. Neurological examination, muscle grip strenght and questionnaires are used to show if kiovig is as effective as Gammagard. the second fase is an open label fase where all the patients receive Kiovig